SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9986e2a432d0a11ead0ce0fc90707f26d122b2bc155d9c52620a21ee346683be' 
  AND token = 'ZnZmabicBa9MpvmoEJaFEQc+18To+HIyK0U/LkY8SSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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