SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '242eb5a82a85c5b84dbe7190817c6f2c589debbbcef128ffde78c361640fbabd' 
  AND token = '4c2s9K0Aidzh/01lhDCT0nWiPzTQcYjg/d6tXXWSMBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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