SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bbb12616461c6a40e63a2d39ca7bd6e5349730a43db091a7928b797c24822e6' 
  AND token = 'OJj1FEoBwoXapyDqX2i4v/20CxAN2acxFyEYyeyZhPM=' 
  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"
    }
  }
}