SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56cccfd98f7f8861dbd86b791a7458633a16428bd7614cf0918c2e2156f96266' 
  AND token = 'G6VxcMzfmJtsoD1VBehiD3u8tQ4+BPvmY8f42Vecaqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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