SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9a25a9dd471f7b050b6b1c43a895d59a723d8edd4602d9516cc5d713d526bdb' 
  AND token = 'GyQwaLI4RQRyjmB9oVYODGONqRw6aUP9Ji7rikFq2I8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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