SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94acb22d0b29bebd91b0fb320f1079a770ced5898fa216d7aae3818bd8bf6d9c' 
  AND token = 'BHr27wAYPuBed69nif78WQGm8WZk1550/uUgLfBgEoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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