SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f9b4b5c2423fe78df4aa01806a717bd6b3d3de318f7c62d8d7bb2060d38af6f6' 
  AND token = 'zg+0ftGEjoSfd20u34lD+xQLFwoZWSewJ8y1kFyUpVk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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