SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '086e892d7dc67a87db84dc8fbb88ec0f793965ab8f1d898703a363db87834182' 
  AND token = 'mGSadoeGNCcGdAawnwqOPmjTa5VoYjSAO/1DCvf8KHc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}