SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab51a132751e6adf3bb6d52341c0ff1dc3223f5998f3c883f79f4814ae8f334f' 
  AND token = 'TIjVUv4HlgqzNJEDfo5q003JjUOQEbY/fypYRIzJlCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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