SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '07b42a6608ea7fb9c22c17cdbafc6a0ff81825a2a55bec0fdfb7efeb8193c39b' 
  AND token = 'IYEslRNLLnPjcZfgAWv4pYmLpsrBTjmCQvCVn2KNsmw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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