SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6423caf5462e7d4461fa3935cc4fd9144c46b1162b1c348330a4ac982acf4d9e' 
  AND token = 'ct/gyBKOooDrjcVO4OfuSqNodnGKiJOFs01jjZT/i2s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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