SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e92b093be5cecac683691f717c89638afc0851b1be30d312cd5ed3eaea2a77a' 
  AND token = '8VW3Adpy3PJ8uaqsB6ZmX35CUnMx71LhPY/tmvI+LdQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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