SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92bb3a2dc31d17d97f47e1eef914020c6a4976e960793a09e53b1889bbe79eed' 
  AND token = '5NjvpLd2c+ukZHI3GuvOySYRZtKieCjQW24qSxqwU/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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