SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ed447ca54197c5b3b7f28e02b2b84c5ae25f4461f59d542a8d6c197b39b7f10' 
  AND token = 'KmyCRbewzXQLKvfAw4rhjpUs8r/SvcOx2OZrmaeLVgk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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