SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3088df81f335e4dd89935e682224e00a1d6417fd962b6b2f9587d59ece547d8e' 
  AND token = 'vzOn4ZIpP+HBNv3l/48tyjeC93xMhGqWMJCr9y9Bm+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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