SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '001f9452dc57f3bd8c040b757e22f9f81c88f5feae58d304f05a680a074b6df4' 
  AND token = 'xIwq/IfJLJ9fGsioDQICPS7h2IZHgv1pbVQdOH4BLhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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