SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'eb185fc582fd1245ebed5c8114abc603d7af7ff14429779f2d76a7bea8579948' 
  AND token = '180aoLha9ZDfu3PBb+HjQum5hVfNFQ4aiZCEm3Vg8BI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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