SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2da528777d283368ab28ab574e2b0444cefcfcbf5ff9d8e492dd5082ef889d29' 
  AND token = 'pZphfVHpoIUahMLA+wdr8WwYVhQcQGqPTe6xwKRQ+CQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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