SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e55db4e94b000178442706368d945dffcb51529263bf57cd2ed1dfcbfe6760a' 
  AND token = 'm/hixI2etwL1KOk2UsFisEv/0Jboh8Mdo9SYPPyRC7Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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