SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15269881634c3ba27b261da3ff8f57d80a102d5cd3b07bd74ec2df897e0a0bbc' 
  AND token = '8PMk/G4MltP7h5xtH3+lqOCPoa4WJs2MU0HGTSahcQU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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