SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4913d9250e3c92b8f18b2dd12437cca5cba42b67e6e47cc3e76d75d7e01de61' 
  AND token = 'kexMTkYaaW6FG/cGehm9c5T5XunOIv2qG7NBnzYfRHU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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