SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8f5ed2771b610f315b5db0ee49936d6e99bf5b512043a116b9654fbc8036d79' 
  AND token = 'oeOKIoeFllu6rNiUkwxIIDsoxn+9LQSrmTz9JZSicEU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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