SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb72e012dd86ded5f3e1254df4238152979b0098fed1b85479570518c3a6becc' 
  AND token = 'GNfGWKDNjrPmSJA4fJSADttEULT02Fyee8TZxwFkKj8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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