SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9dc9e2c6a606d0d73d443d33f69896ad4e99f16fa18bd795d45a242372e4c56c' 
  AND token = '0Q9tuGhASoliv1+BWB/UZEO786UGuGB5mctYkmjubEo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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