SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '50645c426ea444f66179a3f965cb1b4a9dc8fbf980912bd6e6c7c36bbc3022e2' 
  AND token = 'snp8LGtCDz12mdIH1D1kfelhtfj2vVoD9lL5t1Z62XI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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