SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a6419f811b17acb563eb155c4c2453561c729cf3f91e41a4f60a5968851f970e' 
  AND token = '8HBXjGa+GdcwBJUUGi+RA21qNZpxB1tkhcHI2dr4PbY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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