SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2b398956264e88457093e97e780c69eddc973b2f642891aae4f7d48d37712871' 
  AND token = 'JLfbsra8z88WThZw1TynH8oUEaHRwIvsmWAk+NXJNi4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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