SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8245d03ca74f9cbe3798623b2c6175d8b5e08bb92037b41902b9e6b3597f8947' 
  AND token = 'BsN6mgHPjyWw2xVTAFROaAU/yAl4KnSecKiIqYUlUSs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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