SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9dd7154665114f8b4b0b83f011666f4dc6acfe745e6dcb318ed8a99fc6ca53c3' 
  AND token = 'V8ha4eotNJ3T1wRn2/Un1acQJSfqJcnOkUkxdyTQhSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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