SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fc34ac6d74bea08260a0fec90ed59b82ff23c0439ba33685f54ea49dd2b7513' 
  AND token = 'FLHQT4tYmBCGUVgIQR1G0u2Z0cwUfuVJ4F6ADQiVWZw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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