SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '20ea333c1fd0cce51f9e600ff8364956b1e547c6f1784f50ae4d26508dec0202' 
  AND token = 'oU6U7qjfyxE3WWi/miWzKvaCGVwCiPF6zaV+5r22gZ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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