SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f496219c829fdc3b380993fa956c6bec1a5ebc2ee9d8c02a2a05f324bc71be68' 
  AND token = 'oVfEZ1ObHMfnwvgd6T1Si2VG9WBOVECvShPkOKxfSe0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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