SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b278127cbdd9af896017481f28f8cc39c8d20783e38e37467c8a2c845cdfe16' 
  AND token = 'KYqE67AG8F16ZFyNt3FFw5eV5Y9cLouOMqNzPBDx3Is=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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