SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f206ac2f88c1e2e275b00b727d6c098c3b5fcfbb191bc5b63bc3c13291f42641' 
  AND token = 'MIXHrwNO2bS7qR0FbkyDI4EpC+yrdHlHBEpJPVKuCig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}