SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '72b7481dad2aec57c145a438b4211c796c253c4f47fe7913eada7809707baf40' 
  AND token = '5txq14rbZGhwfzBS/iWXd8XYKBEuDozT2/F3VXG1Vv4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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