SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe3fe1dd64fad84edf1c42ada9542a9c277d7cb6bfed901a89459e67c5387fec' 
  AND token = 'k3Iee+K3ufLmnWflF1FSq+gP6ct7vPydnKWqvjrBUlY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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