SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29b4b345b2fe3ddb1ff7ccff07eacb69dcaedd2b29938479afb4b6d94b49f773' 
  AND token = 'Obz2ruTq2hE7Zf2vT66m7OyOLKnN2GolMx+XyuAq8+M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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