SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'adc9737294f945735c0c390e1ed9bdf614b1d3ff78d7b246dd7a2862895d181a' 
  AND token = '+GJ9ze9nf6XEo64IZgTW+NBesYrbFg5h8TyBseT0HE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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