SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '43078898746e0bc83dbc36f7f7f38392f17fa8569ba728419c16da543f8c622b' 
  AND token = 'jaIPBpE99gLvrwY51gxDF5CboUvVz0syyGXsgXSEOPE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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