SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa6fca34b7999fa5d0eed425ad0d4b70ca85809ce891c092b07016bce8872264' 
  AND token = 'Y1Dpy45Kehtvq2hqSz2HDRzC0Hh7qJa/Cs4MwNR+KgU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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