SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b83e42b0c142d1dc792d6ad5c8cc66034648454c5e176dcc44c62da6f34293a5' 
  AND token = 'm1uusaYyvm4agRGVHYU1PPiQb3JjxWdE0/pnS+o7/Xs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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