SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2bd4d020072f08218b87a763f0f69b0f1f7c53aec3d996e3870da2df53866d6' 
  AND token = 'SNGXpX9i07scYZykacLbJBKipka7aey1YzPNG7Pz6Yo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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