SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0c98126b93c262a3a17510a4475e006b488558f8d08ff488b24d3aed344d55a6' 
  AND token = 'uhar0S22/YbZaweQURX8nbBVk59a5qHACjG4PE9Bm/A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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