SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7764111a01bed72315f7256e8ec030550666f23e2137b8bfa2565a64efff36b' 
  AND token = 'Qyx2LTenMbOdcwcPeZs0owvPxNkVFqiYXvZtap43aaY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}