SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '5eb4aa2a469395b8b0f22e7c5d812f04b2c2cda190cc39790d03ec41c5a85605' 
  AND token = '94CbTrWoiiyG0WXXAiVmVY35EIjw9c2US5DhyHNYtMI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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