SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95841c04bd47056311133277a293e8bd6cfb3643cfc44d1bd20270a1538723ab' 
  AND token = 'b18PMg8HL9o3Qh5OxrbKm97+VzMDqYGvVZQzc8R7+DU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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