SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11ce159efcaae27da645a0246ad75c23a6d5f960b9500afa1143e2fd883584e0' 
  AND token = 'zZ2MfRIxr0+Dky6ZiQIl890yYxkBCRx956pWWCcqUxQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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