SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7be89b2cfb3a23aac877cebf3dd30127506b6079a463dcf9b5260390696762a8' 
  AND token = 'l7M0raDXlHOdy0uHA7CJ9Mse48iZ2n/ml5XoCyrrulU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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