SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f87e0bde80a381e203336c9652651105142f35de201246308a0bba2c6d956676' 
  AND token = 'QiP+hFteKaFH2SaMHdqi9ntFjjk772waFzc0QgtDovk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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