SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4db37caeb68c93d693117ca5c10670f85209c24a4e262e7c20d719b179c2ed25' 
  AND token = '8jnHf/UgfwNNTBsRuoKEMObfW9hcXewUxSQw3zlLdbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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