SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b2c98ce695b5caefbda0aae536a81880c5bde2582374dfb53df4c7a3ba600ed' 
  AND token = 'UAFsXW7LrgnSghVbGs3vw6s3FAliqSIrIk5qF5UAZGs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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