SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f30a45daebfe4f74cc667c5b0f608e76118d20db17a2d9974656ecd80b8bf69' 
  AND token = 'JuIL4m1ZK97fO6pyoTmoNTpEZtOhgnXGm+gIUzozD0Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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