SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46f1f5d0a433eb941e4c73c3e82206b533134892386a56c81c5be8bc55d53f8b' 
  AND token = 'AjPw3INJXd8R21KfcY/AHTIutHOKYGuSdxqlw9Nb0lg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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