SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3f54e4f176b58eb2fdd18725a619d4bdde4548df1e7ee79b8176abfaf0307fc1' 
  AND token = 'CB+JvBqNAKSRyMQ8wd507t70OZUst+VsJPHdKgaTDFk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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