SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f574775065e36e53bdb2dee7060eb5ff3e4a1059a77beb679f21e8603a1ee612' 
  AND token = 'llL2t5Fpas7bISBXKd/idH12Qzv7zD6BAY8MQM3ANvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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