SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7caa6caed74dc93b24fcb6ef066635c46912c18a529113b2b8266c6efbc193ac' 
  AND token = 'T+NqT6fuEcGAHNgJcmjskCQd7MMpoMPCjrQmUyMdifk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}