SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6dc17db27d08192a56c5555e1779444ae8e3b371c67f95acaf9a5c6a3d680de7' 
  AND token = 'h14mj/oWFU8VEzqv4fHi+QpKmBahK2dGUNixFkNZvbY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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