SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '029278df32d76e2f3c0ca6fea56ec2b76aa283df73f5d3bc03a9bb6f3e688d5f' 
  AND token = 'v9wZUOh1pQuLgqNTBJeKIGvfzGKcy1ff/fbiSo5bs7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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