SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27c77f4ffee624dffa3d0a9244272bd81cfc3bba8af7c19a0be57b998d44faa5' 
  AND token = 'uquBXhkxvLoC4DkbKwGPYcAlyVK+HjPxgUnmlN2dO8k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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