SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8a8aa48dc09046b2a3d8ec4040a6dbe501adba0efe2d99e494d4bac2bb3ee89' 
  AND token = 'UvTIRg8lvFXAhDPCkq3/gCuJVvDrOdq7wuMYig3WXMo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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