SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe57a032e16c9172838bdb5961417e7894775604dfb689d3a035fc3bd4f7015b' 
  AND token = 'gTylBBZv3zsx/srD/mWBLpu9ATedUtwzdogGmQD+waQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}