SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1ae7e8a4b5b4b6841495764f6b0c3a4d4c0e84fc82525d1276cae48d2bb9f6f' 
  AND token = '1HZlXmu1HF6vxB8YpJqgQbtp6YqxjwN8ZgBveChFEEA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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