SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45f6381ab9c62f5d335591820378d2ded3f735a28e683166a9d39406334728f6' 
  AND token = 'OKlJdPBuNhsleMlNUCk65zZPehElE3fbWbqHRk/8vqw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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