SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75200f88e90955c4f590dc47ed0e230ebe4324475699698fee33663f4a267dd7' 
  AND token = 'mGcPnGdSh25n/eT3maiqG37jCcwzHGhVaIKbPBK+zY0=' 
  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"
    }
  }
}