SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59ed489d96a842f54edaab4f608500f9f3e130c18835d469406e54add4cd87ca' 
  AND token = 'bh7vWtQhMGyPAzHYC4kgW7AelWmhrTeCCAUlg+WU8hQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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