Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8dcea9c6592519a6fdadb0a26960b47699d000de2e5906da2f0f1a2c2a7de1af' 
  AND token = 'vdU7Va4yjAE6fhKpu1RXiQwRQAVEGlvrIqvMUwe0FeQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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