SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '99ea4ab4381d3616f39784d1576a80494d849c0f92ce9cae4868a38274515da6' 
  AND token = 'fRa9hGdihl68uReiqa0NpcOHCipT/oAZlQF7Hk9EhjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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