SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e5bd2cac9f0c26fad0dfefb67fa79e767edb7e4a90ab63327773859dec66b99' 
  AND token = 'Rw95tCOLgW0vwtYz1AGFVlQpC6p/SRs7be0kLKPo8gY=' 
  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"
    }
  }
}