SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9da4d731e659e7e3278cb7612f52d1374d4a7f330621d3f3063d466432b4f834' 
  AND token = 'LMl72dMu0aQiz1Rup0njTeVkB2TAGeVyKQp1TH7RsUo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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