SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ade75c7e4f094be9da9a35ce959e415e41cc312145a30284d9aac97bb28f9b47' 
  AND token = 'NdpOawwwR8Y7y2RrHl2ftmsSxWKVP0LSmuJKGQcsOx0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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