SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df6efcc5fca9cbe45991e40b13fb9e6630c9fd29217f63126135a49fe4828ef3' 
  AND token = 'O4g6gPXnNJTWZsZfzQc3bwWnazoMFZguKSoMCQ2ahCc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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