SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b570fc84f9397b2f74404f9f1646e8c5832ae6f9ff9053f417e77b4d55d0008' 
  AND token = 'RQHXcuBXlZ8BzG191jQmMV4aCZNowgxpTHPd8q5ZLxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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