SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3cff9b2830745b39d2a7538350dd1570d3f0ce2dab042af3b174193ebfa4e47' 
  AND token = 'Fy+mApmDsvuOxKuYQHaArGlS0361lZoxgKD95piBE4Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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