SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06d38ff3104c2ab185286667d4c79e09b51232af78f4714b72d6629a2db4ec3c' 
  AND token = 'ABeIlaXwgHiD8j/zRjP09s3kI+mGzloBosujwRdqYZk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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