SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d8577035d9e89f75d1735c6f14014cc2c2967dca0c46d34f69630d1bbf6ef46' 
  AND token = 'C/5g+XVM4WWanpCsXRGwcSIxV3zTGaTnq/kCH7bD9+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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