SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '789e7a09b7531603377e778511147e7ba7b94e4e60caefd20d5bab36b7c38673' 
  AND token = 'ElOeZwVvK/pLlvSqA2Xj3IQ9wT/JTkmCo/oprRlWBJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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