SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c2da7340ab52cedbbf570cc3a816f3755303f5c405eecf7953206eae5146321' 
  AND token = 'pSY8zGnj2hh/Lt16tsRSUhyw4USyllcFW1Xriyw1bJ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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