SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5735953e53993bf2beec71b1e32e125d54fe47fdd1f96f0c41253af2640658fd' 
  AND token = 'N1rUZPI/n+bWlgYSYFodb6pWV12AQFAdF7MXW/AI6WU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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