SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee9f0e8253c9510d82b127a1d72f12ff88a490fd61ae6651541dec98a6c7f0c1' 
  AND token = 'DqWupHcd6ccyyUlVHR4E6GiO/+NWHbiqXh629KITePw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}