SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '143709afe683af380deb73472c9de6bb2b7d213fa47bff62c4f8c6d5e902e529' 
  AND token = 'JUg1MFGSKTjAMP21Hg5DxwuISWBFb+JhUCU678zRQC4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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