SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70d4c6698302252aa3ed94ee66ef29ba24b761d044218ad6921e5cccb66fbb54' 
  AND token = 'U6KSLMHo4yHLU9QBrysQQrijA8T3hCq9rsHcXN3cots=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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