SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb4b8b62155827aead4a2af0dcafc79e31a35773ca83a9f51e4b1a72e7c91541' 
  AND token = 'I+yrf0mDxsYaCIM8UqvtPjlR81RYOrziKRd6gUYRR4g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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