SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f218781616e093cde57122f725283ce1ca22ad3a4a2e4b887bc80574e17bf45c' 
  AND token = 'PjSEUrZAXPwDaug7dMjycoz4i3Oax+lYSuB3ksUAZ1g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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