SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba10f08219a53734e0899bd6733bd9cbd9dc904c141c0b523281bd91371bd873' 
  AND token = '9i0GrwagK4G04i9eHNdwrrdJ2ierZe0pmtncMOSUKrk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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