SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '160c329d0883bbed681bfa8f0c0743bca1f2518b837205ab7e3dca50acd025a8' 
  AND token = '8XG9nnMLTP28Wsj8viF5cwa3yfD82FfrVevnygVk74w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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