SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da6520e0efc95ffdfd3ce8958725498ea7747a7acf968f37a995f60d6116d256' 
  AND token = 'AYAsOvvWDqKvSElc3aLr7wmu9E2OVwepNwFb/q10PaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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