SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c290372129fc9c6a5db8efc1da6ff8da4bf28a2743e6a1053bff11a1577e0b0' 
  AND token = 'o2SStO6I4Z7TE6RA8n+KPnDvB+wKODaI2+hmRe5mWaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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