SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02506ce2518025db3aa571e6332bc7fe4b713c81473211f26f0c56cc0b856617' 
  AND token = 'V+Rse2VZYfXXoRw8QK7WXR4AEAbd2t3lXAG5ir1JjwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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