SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '822fd6c2f864997b86d4b3d5275c36e896d53e573622b88fd9be6f17c0567c64' 
  AND token = '7VPFOOTgZZH4kmkiERb+Ft1FYUiByzRGv6dvJ/5rhnE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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