SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '96a0b66b229fa95a12e04a5443b3f340b2d2e17ec6bc1867d264b3d75fc047f3' 
  AND token = 'MrqtPvvfJJXxVeOQ+KXpC8P/RfFPnO/hMCaLYk7d9s4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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