SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5ebb5cfa3087bd73105ccf4ad1da36cff1bf37516e849813ba62308b0628c973' 
  AND token = 'HMLX5nwfRnGm/VjN9x5pH5fvEY5gm9JuPt6vAu0DMTY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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