SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f0ad3075307b68209f3bd75ddf2260c5f4b895284b3885eeb763b1b06f75466' 
  AND token = 'H5tEGmUZKi1rQcLjPK9TCzOnucIEEMT5w5yXcA5brVE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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