SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a3ba48151f497d7da44da946c526d36d9e162fc90c201afa3fcc221c8e9e28a' 
  AND token = 'ZzjcQ0nFogUMe8Ge5hnZYR+qjxNNs/BxoJ+A3bUlrFo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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