SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5290a5e2808d0ae1b2c5401cfda5582913ffaa2ace3760c8b1c4adff6e4861a6' 
  AND token = 'b1vyijkL+rSG1Hwzg+l5C6ogKVNQ398PCSw9mRVbW1M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00068

JSON explain

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